TWI466976B - Hot peeling double sided adhesive sheet and processed body processing method - Google Patents

Description

Thermal peeling double-sided adhesive sheet and processing method of processed body

The present invention relates to a heat-peelable double-sided adhesive sheet and a method of processing a processed body using the same, and more particularly, relates to a method for rapidly reducing adhesion by heat treatment, and is suitable for processing surface unevenness A heat-peelable double-sided adhesive sheet of a workpiece and a method of processing the object to be processed using the same.

Heretofore, a heat-peelable adhesive sheet in which an adhesive layer containing heat-expandable microspheres is provided on a substrate is known (for example, Patent Documents 1 to 4). It can reduce the adhesion by foaming or swelling treatment caused by heating the adhesive layer, so that it can be easily peeled off from the adhesive body, for example, for the manufacturing step of the ceramic capacitor or the temporary fixing of the grinding step of the semiconductor wafer. Wait. In particular, in order to prevent wafer damage during transportation, the pedestal of a support having substantially the same size as the wafer is bonded to the wafer in order to prevent breakage of the wafer during transportation. the way.

Patent Document 1: Japanese Patent Publication No. Sho 51-24534

Patent Document 2: Japanese Patent Laid-Open No. 56-61468

Patent Document 3: Japanese Patent Laid-Open No. 56-61469

Patent Document 4: Japanese Patent Laid-Open No. 60-252681

However, in recent years, high-performance semiconductor wafers have formed large protrusions represented by bumps or larger pits represented by transistors on the wafer pattern surface. Wait. When the adhesive sheet is bonded to the semiconductor wafer, the sheet conforms to the surface shape of the wafer, and as a result, the surface shape of the wafer is transferred to the back side of the sheet. In this case, when the support is bonded to the pedestal, the bubbles are pressed against each other or the support is lifted around the wafer. Therefore, after the back surface of the wafer is ground, water ingress or cracking of the wafer occurs.

Accordingly, an object of the present invention is to provide a heat-peelable double-sided adhesive sheet which is processed on a side of a heat-peelable double-sided adhesive sheet and a processed body using the heat-peelable double-sided adhesive sheet When the surface of the object to be processed is bonded to the other side and the support is bonded to the other side as a pedestal, when the back side of the object is processed, even if there is a large unevenness on the surface of the object, the support does not rise. Or, in the process of processing, cracks occur in the object to be processed.

As a result of intensive studies to solve the above problems, the present inventors have found that when a specific substrate is used as a substrate in a heat-peelable double-sided adhesive sheet, it is possible to prevent use as a workpiece having a large surface unevenness. The present invention has been completed by the lifting of the support of the pedestal or the occurrence of cracks in the workpiece during processing.

That is, the present invention provides a heat-peelable double-sided adhesive sheet characterized in that it is provided with a heat-peelable adhesive layer A on one side of a substrate and a heat-peelable double-sided adhesive sheet on which an adhesive layer B is provided on the other side. And the substrate comprises a porous substrate.

In the heat-peelable double-sided adhesive sheet, the porous substrate preferably has a density of 0.9 g/cm ³ or less and a tensile modulus of 20 MPa or less. The substrate may be composed of a laminate of a porous substrate and a non-porous substrate. As the adhesive constituting the adhesive layer B, for example, a pressure-sensitive adhesive, an ultraviolet curable adhesive, a heat-peelable adhesive, a thermoformable adhesive, a thermosetting adhesive, or the like can be used.

Further, the present invention provides a method of processing a workpiece, comprising: bonding the object to be processed to any one of the heat-peelable adhesive layer A and the adhesive layer B of the heat-peelable double-sided adhesive sheet; The bonding step of bonding the support to the other; the processing step of processing the object to be processed; and the peeling and recovering step of peeling and recovering the workpiece by heat treatment after processing the object.

In the processing method of the workpiece, examples of the workpiece include an electronic component, a semiconductor wafer, and the like. This method is particularly suitable for laminating an adhesive surface of a heat-peelable double-sided adhesive sheet having a maximum surface unevenness of 10 μm or more, and processing the object to be processed having the above surface.

According to the present invention, since the porous substrate is used as the substrate, the unevenness is excellent, and the workpiece having a large surface unevenness such as a bump wafer can be subjected to a thin grinding or the like by using a pedestal of the support.

Hereinafter, the present invention will be described in detail with reference to the drawings as needed. Fig. 1 is a schematic cross-sectional view showing an example of a heat-peelable double-sided adhesive sheet of the present invention. In this example, the heat-peelable adhesive layer 2 is provided on one surface of the substrate 1, and the adhesive layer 3 is provided on the other surface, and the separator 4 is laminated on the heat-peelable adhesive layer 2 and the adhesive layer 3.

The base material 1 is a support base of the heat-peelable adhesive layer 2 and the adhesive layer 3, and includes a porous base material. The base material 1 may be composed only of a porous base material, or may be composed of a laminate of a porous base material and a non-porous base material. In the present invention, at least the porous substrate is used as the substrate. Therefore, when the heat-peelable adhesive sheet is attached to the object having a large surface unevenness, the volume of the uneven portion is absorbed, so that the back surface side of the adhesive sheet does not appear. Concave shape. Therefore, when the support is bonded to the back side of the adhesive sheet by the pedestal, it is possible to prevent the occurrence of water ingress or cracking of the wafer after grinding the back surface of the wafer due to the mutual crushing of the bubbles or the lifting of the support.

The material of the substrate 1 can be appropriately selected within a range that does not impair the usability of the adhesive sheet, and the like, and may be a thermoplastic resin, a thermosetting resin, an elastomer, or the like. Examples of the material include an olefin resin such as polyethylene or polypropylene; a polyester resin such as polyethylene terephthalate or polyethylene naphthalate; and a polystyrene resin such as polystyrene; Vinyl resin such as polyvinyl chloride; polyurethane resin; acrylic resin such as polymethyl methacrylate; acrylic acid-urethane copolymer; cellulose resin; polycarbonate resin; Amidoxime resin; polyimine-based resin; polyamine-quinone imide resin; polyfluorene-based resin; fluorine-based resin; plastic film or sheet such as rubber-based polymer.

The porous substrate may be formed by any method. For example, any one of the following may be used: a porous film obtained by casting a polymer solution into a film form and then introduced into a coagulating liquid; a porous film obtained by the treatment; a porous film obtained by removing the fine particles from a film for removing fine particles by a dissolution treatment or the like; and performing imprint processing on the film And a porous film obtained by melt-treating a powder of a polymer by heating; a foamed film which is foamed by using a chemical foaming agent or a physical foaming agent; and having a small thermal expansion property A film in which a hollow filler such as a ball or a hollow glass bead is dispersed. The average particle diameter of the hollow glass beads can be appropriately selected in consideration of the thickness of the porous substrate, etc., and is usually 3 to 200 μm, preferably 10 to 100 μm. In addition, the average particle diameter of the heat-expandable microspheres may be appropriately set in consideration of the thickness of the porous base material or the like, and is, for example, 3 to 100 μm, preferably 10 to 100 μm after thermal expansion.

Preferable examples of the porous substrate include a sheet material obtained by the following, that is, a urethane polymer, an acrylic monomer, a photopolymerization initiator, and hollow glass beads or The mixture of the heat-expandable microspheres is applied onto a non-porous substrate or the like to form a coating film, and then irradiated with ultraviolet rays.

The density of the porous substrate is not particularly limited, but is generally 0.9 g/cm ³ or less (for example, about 0.2 to 0.9 g/cm ³ ), preferably about 0.25 to 0.7 g/cm ³ . The sample size (vertical and horizontal) was measured with a steel ruler at room temperature of 23 ° C and a humidity of 50%, the thickness was measured by a 1/1000 mm gauge, and the mass was measured by a weight of 1/1000 g, thereby mass / Volume to determine the density (weight measurement method). When the density of the porous substrate exceeds 0.9 g/cm ³ , the unevenness absorbability is lowered, and the adherend cannot be held.

The tensile modulus of the porous substrate is not particularly limited, but is generally 20 MPa or less (for example, 0.1 to 20 MPa), preferably about 0.1 to 15 MPa. The tensile modulus of elasticity was determined as the initial modulus of elasticity based on the stress-bending curve using a tensile load measuring machine. When the tensile modulus of the porous substrate exceeds 20 MPa, the unevenness absorbability is lowered, and the adherend cannot be held.

The thickness of the porous base material is not particularly limited, but is generally from 10 to 1,000 μm, preferably from 25 to 500 μm, more preferably from about 50 to 300 μm, from the viewpoints of cutting properties and unevenness absorption. When the thickness of the porous substrate is less than 10 μm, the unevenness absorbability is liable to lower, and when it exceeds 1000 μm, the cutability is liable to lower. Further, when the substrate 1 is composed of a porous substrate and a non-porous substrate (for example, a non-porous substrate including polyethylene terephthalate or polyimide), the substrate is The total thickness is, for example, 20 to 1100 μm, preferably 35 to 550 μm, more preferably 60 to 350 μm.

When the base material 1 is composed of a laminate of a porous substrate and a non-porous substrate, the laminate can be produced by a conventional film deposition method such as a coating method, an extrusion method, or a dry lamination method.

The heat-peelable adhesive layer 2 is, for example, expanded or foamed by heating, and reduces the adhesion to the adherend (the processed body) to exhibit a peelable layer. The heat-peelable adhesive layer 2 is generally composed of a foaming agent such as a heat-expandable microsphere and a binder. As the binder, a polymer or a wax which allows the foaming agent such as the heat-expandable microsphere to be foamed and/or expanded by heating can be used. Among them, it is preferred to use foaming and/or expansion of a foaming agent such as a heat-expandable microsphere as much as possible. From the viewpoint of the thermal expansion property of the foaming agent such as the heat-expandable microspheres or the controllability of the adhesive properties such as the adhesion of the adherend, the binder is particularly preferably an adhesive.

The pressure-sensitive adhesive is not particularly limited, and for example, a rubber-based polymer, an acrylic polymer, a vinyl alkyl ether polymer, a polyoxymethylene polymer, a polyester polymer, or a polyamide polymer can be used. , urethane-based polymer, fluorine-based polymer, styrene-diene block copolymer system, etc. An adhesive for a polymer, or an adhesive for improving a latent property in a hot-melt resin having a melting point of about 200 ° C or less, or a radiation-curable adhesive, or a crosslinking agent (for example) For example, polyisocyanate, alkyl etherified melamine compound, epoxy compound, etc.), tackifier (for example, rosin derivative resin, polyterpene resin, petroleum resin, oil-soluble phenol resin, etc.), plasticizer, softener Various additives such as a filler, a pigment, a coloring agent, an anti-aging agent, and a surfactant, etc. (Japanese Patent Laid-Open Publication No. SHO 56-61468, Japanese Patent Laid-Open No. 61-174857, Japanese Patent Laid-Open No. Japanese Patent Publication No. 63-17981, Japanese Patent Laid-Open Publication No. SHO 56-13040, and the like. These adhesives may be used singly or in combination of two or more.

As the adhesive constituting the heat-peelable adhesive layer 2, it is preferable to use the self-normal temperature to the viewpoint of the controllability of the moderate adhesion force before heating the adhesive body and the balance of the reduction of the adhesion force due to heating. A polymer having a kinematic modulus of from 50,000 to 10,000,000 dyn/cm ² in a temperature range of 150 ° C is a matrix polymer.

In general, as the above adhesive, a rubber-based adhesive using natural rubber or various synthetic rubbers as a matrix polymer; and an alkyl (meth)acrylate (for example, methyl ester, ethyl ester, propyl ester, isopropyl, butyl, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, isodecyl acrylate, dodecyl acrylate, eicosyl ester C _1-20 alkyl ester) of one kind Further, two or more kinds of acrylic polymers (homopolymers or copolymers) used as a monomer component are used as an acrylic adhesive for a matrix polymer.

Furthermore, the above acrylic polymer has cohesive force, heat resistance, and crosslinkability. For the purpose of upgrading, it may optionally contain units corresponding to other monomer components copolymerizable with the above alkyl (meth) acrylate. Examples of the monomer component include a carboxyl group-containing monomer such as acrylic acid, methacrylic acid or itaconic acid; an acid anhydride monomer such as maleic anhydride; (hydroxy)ethyl (meth)acrylate and (meth)acrylic acid; a monomer having a hydroxyl group such as hydroxypropyl ester; a monomer having a sulfonic acid group such as styrenesulfonic acid or allylsulfonic acid; or a monomer having a mercaptoamine group such as N-hydroxymethyl (meth)acrylic acid decylamine; (amino)alkyl (meth) acrylate such as aminoethyl (meth) acrylate; alkoxyalkyl (meth) acrylate such as methoxyethyl (meth)acrylate; a maleic imine monomer such as N-cyclohexylmaleimine; an Ikonium imine monomer such as N-methyliconazole; N-(methyl) propylene oxime Amber quinone imine monomer such as succinimide; vinyl monomer such as vinyl acetate, vinyl propionate, vinyl pyridine or styrene; cyanoacrylate monomer such as acrylonitrile or methacrylonitrile; An epoxy group-containing acrylic monomer such as glycidyl (meth)acrylate; a glycol-based acrylate monomer such as (meth)acrylic acid polyethylene glycol; (meth)acryl An acrylate monomer having a heterocyclic ring, a halogen atom, a ruthenium atom or the like such as tetrahydrofurfuryl ester, fluoro(meth) acrylate or polyoxymethylene (meth) acrylate; diol di(meth)acrylic acid Polyester, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyester acrylate, urethane acrylate, etc. Monomer; an olefin monomer such as isoprene, butadiene or isobutylene; a vinyl ether monomer such as vinyl ether. These monomer components can be used alone or in combination of two or more.

Examples of the heat-expandable microspheres include the following microspheres. A material which is easily vaporized by heating isobutane, propane, pentane or the like is enclosed in an elastic shell (shell). The above shells are often formed of a thermally fusible substance or a substance that is destroyed by thermal expansion. Examples of the material for forming the above shell include a vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and poly. Hey. The heat-expandable microspheres can be produced by a conventional method such as a coacervation method, an interfacial polymerization method, or the like. In addition, the heat-expandable microspheres are also commercially available, for example, under the trade name "Matsumoto Microsphere" [made by Matsumoto Oil & Fats Co., Ltd.].

By using the heat-expandable microspheres, it is possible to stably control the degree of contamination of the adherend due to heating. The foaming agent or the like which is not microencapsulated may agglutinate and damage the adhesive layer or the like, resulting in a lack of suppression effect of increasing the degree of contamination. In order to effectively and stably reduce the adhesion of the heat-peelable adhesive layer by heating, it is preferred that the volume expansion ratio is 5 times or more, particularly 7 times or more, and particularly 10 times or more, it is not broken. A moderately intensifying heat-expandable microsphere.

The average particle diameter of the heat-expandable microspheres can be appropriately selected depending on the thickness of the heat-peelable pressure-sensitive adhesive layer 2, etc., and is generally 100 μm or less (for example, 1 to 100 μm), preferably 80 μm or less (for example, 1 to 80 μm), and more preferably It is 1 to 50 μm, but is not limited thereto.

The amount of the foaming agent such as the heat-expandable microspheres can be appropriately determined depending on the expansion ratio of the heat-peelable pressure-sensitive adhesive layer 2 or the decrease in the adhesion force. In general, when the binder is an adhesive or the like, it is 1 to 150 parts by weight, preferably 10 to 130 parts by weight, based on 100 parts by weight of the matrix polymer. Good is in the range of 25 to 100 parts by weight.

The thickness of the heat-peelable pressure-sensitive adhesive layer 2 can be appropriately selected in consideration of adhesion and reduction in adhesion at the time of heat peeling, and the like, and is usually 300 μm or less (for example, 1 to 300 μm), preferably 2 to 200 μm, more preferably 5~150μm. When the thickness is too small, the surface is roughened due to a foaming agent such as a heat-expandable microsphere, and sufficient adhesion cannot be expressed. Moreover, when the thickness is too large, the adhesion reduction due to the heat deformation failure is insufficient, and the peeling of the adherend cannot be performed smoothly.

The method of forming the heat-peelable pressure-sensitive adhesive layer 2 can be carried out, for example, by a method such as a method of mixing a foaming agent such as a heat-expandable microsphere with a solvent, a binder, or the like, and expanding the composition by a coating method or the like. The mixture forms a sheet-like layer. The above mixture may be directly applied onto the substrate 1 or the like, or may be applied onto a suitable separator (release paper or the like) to form a heat-peelable adhesive layer, which is then transferred onto the substrate 1.

The adhesive layer 3 is not particularly limited, and may be a pressure-sensitive adhesive such as a rubber-based or acrylic-based adhesive, an ultraviolet-curable adhesive, a heat-peelable adhesive, a thermoformable adhesive, or a thermosetting adhesive. Adhesive composition. As the rubber-based or acrylic pressure-sensitive adhesive, those exemplified as the rubber-based pressure-sensitive adhesive or the acrylic pressure-sensitive adhesive can be used. It is also possible to add, for example, a crosslinking agent (for example, a polyisocyanate, an alkyl etherified melamine compound, an epoxy compound, etc.), a tackifier (for example, a rosin derivative resin, a polyterpene resin, a petroleum resin, or an oil) to the adhesive. Various additives such as a soluble phenol resin, a plasticizer, a softener, a filler, a pigment, a colorant, an anti-aging agent, and a surfactant.

When the base material 1 is formed of a laminate of a porous base material and a non-porous base material, the adhesive layer 3 may be provided on either the porous base material side surface or the non-porous base material side surface.

The thickness of the adhesive layer 3 is not particularly limited, and is usually in the range of 0.1 to 500 μm, preferably 1 to 300 μm, more preferably 5 to 250 μm from the viewpoint of cutting property or peeling property after the processing.

The heat-peelable double-sided adhesive sheet of the present invention may take a suitable form such as a sheet shape, a belt shape or a label shape. Moreover, at this time, the separator 4 may be temporarily adhered to protect the heat-peelable adhesive layer 2 and the adhesive layer 3. As the separator 4, for example, a suitable release agent such as a polyfluorene-based, long-chain alkyl-based or fluorine-based coating can be used for the plastic film or the paper coating.

In the processing method of the present invention, the object to be processed is bonded to one of the heat-peelable adhesive layer 2 and the adhesive layer 3 of the heat-peelable double-sided adhesive sheet of the present invention, and the support is bonded to the other. a bonding step; a processing step of processing the object to be processed; and a peeling recovery step of processing the object to be processed by peeling and recovering the object to be processed by heat treatment.

The object to be processed is not particularly limited, and examples thereof include electronic components such as ceramic capacitors, and semiconductor wafers. In the method of the present invention, the substrate comprises a porous substrate, so that even if it is attached to the surface of the heat-peelable adhesive layer 2 on the side of the heat-peelable adhesive layer 2, the adhesive body having a large unevenness is used. The porous substrate can also be moderately absorbed in volume and absorb the irregularities. Therefore, when the adhesive layer 3 of the heat-peelable double-sided adhesive sheet is attached with a rigid support (table), no irregularities are formed on the adhesive layer 3, and a smooth surface can be maintained, so that good support can be obtained. Attached to the state. Therefore, posted After the support (stage) is supported by the workpiece, the workpiece can be processed without abnormality such as breakage or water. Therefore, for example, a processed object having a surface unevenness difference of 10 μm or more (for example, 10 to 150 μm, particularly about 15 to 50 μm) on a semiconductor wafer or the like in which a bump is formed on a semiconductor wafer or a transistor such as a bump is formed. When the back surface is processed (for example, grinding, etc.), it can exert a particularly large effect.

The type of processing is not particularly limited, and examples thereof include processing such as grinding, cutting, assembling, laminating, and calcination. The heat treatment after the processing can be performed, for example, by a suitable heating means such as a hot plate, a hot air dryer, a near-infrared lamp, or an air dryer. The heating temperature is not less than the thermal expansion starting temperature (starting foaming temperature) of the foaming agent such as the heat-expandable microspheres in the heat-peelable pressure-sensitive adhesive layer 2, and the heat treatment conditions can be appropriately set depending on the heat resistance of the adhesive body, the heating method, and the like. . The general heat treatment conditions are: temperature 100 to 250 ° C, 1 to 90 seconds (heating plate, etc.) or 1 to 15 minutes (hot air dryer, etc.).

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the invention should not be construed as limited.

Example 1

UV (ultraviolet) reactive urethane amide containing 50 parts by weight of urethane polymer, 40 parts by weight of butyl acrylate, 10 parts by weight of acrylic acid, 0.15 parts by weight of photopolymerization initiator In the syrup A, 10 parts by weight of hollow glass beads (average particle diameter: 67 μm) was blended with respect to 100 parts by weight of A to prepare a UV-reactive urethane syrup B. will The UV-reactive urethane syrup B was coated on a PET (polyethylene terephthalate; polyethylene terephthalate) film having a thickness of 25 μm to a thickness of 400 μm, and after drying, a total thickness of 325 μm was obtained by UV irradiation. A porous film with PET (a porous substrate layer comprising an acrylic-urethane copolymer/PET film). Further, in an acrylic polymer A containing 100 parts by weight of butyl acrylate and 5 parts by weight of 2-hydroxyethyl acrylate, 3 parts by weight of an isocyanate crosslinking agent is blended with respect to 100 parts by weight of A, 25 parts by weight of a heat-expandable microsphere "product name "Matsumoto Microsphere F301SD", manufactured by Matsumoto Oil & Fats Co., Ltd.) to prepare a heat-peelable adhesive A, and apply the heat-peelable adhesive A to a PET separator After drying, the obtained heat-peelable adhesive layer having a thickness of 25 μm was transferred to the porous side of the porous film. Further, in an acrylic polymer B containing 50 parts by weight of butyl acrylate, 50 parts by weight of ethyl acrylate, and 3.5 parts by weight of acrylic acid, 0.5 parts by weight of an epoxy system is blended with respect to 100 parts by weight of B. The acrylic adhesive B was prepared by applying a crosslinking agent to the PET separator so as to have a thickness of 20 μm, and then transferring it to the PET film side of the porous substrate. Thereby, the heat-peelable double-sided adhesive sheet A was obtained.

Example 2

To the acrylic polymer containing 100 parts by weight of butyl acrylate and 4 parts by weight of acrylic acid, 2.5 parts by weight of an isocyanate crosslinking agent is blended with respect to 100 parts by weight of the acrylic polymer [trade name "CORONET" L", manufactured by Japan Polyurethane Industry Co., Ltd.], 40 parts by weight of heat-expandable microspheres [Product name "Matsumoto Microsphere" F80VSD", manufactured by Matsumoto Oil & Fats Co., Ltd., to prepare a heat-expandable adhesive, and apply the heat-expandable adhesive to a PET (polyethylene terephthalate) film having a thickness of 50 μm, and then apply it at 160 ° C. In the heating step, the thermally expandable microspheres were swollen to obtain a PET-attached porous film (a porous base material layer/PET film containing an acrylic copolymer) having a thickness of 170 μm. Hereinafter, the heat-peelable double-sided adhesive sheet B was obtained by the same operation as in Example 1.

Comparative example 1

The heat-peelable double-sided adhesive sheet C was obtained by the same operation as in Example 1 except that the hollow glass beads were not blended. Further, the layer structure of the substrate is a non-porous substrate layer/PET film comprising an acryl-urethane copolymer.

Comparison column 2

A heat-peelable double-sided adhesive sheet was obtained by the same operation as in Example 1 except that a PET film having a thickness of 250 μm was used as the substrate.

Evaluation test

The thermal peeling property obtained in the example or the comparative example was bonded to a full array bump wafer (surface maximum unevenness: 40 μm) having a wafer size of 10 mm × 10 mm, a bump height of 40 μm, a bump pitch of 130 μm, and a wafer thickness of 725 μm. After the heat-peelable adhesive layer of the double-sided adhesive sheet was adhered to the adhesive layer on the back side, a glass wafer (support) having the same diameter as that of the bump wafer was bonded, and the lifted state of the glass wafer was visually observed. Thereafter, the back surface of the bump wafer was ground to a thickness of 75 μm, and the presence or absence of wafer cracking was visually observed. Finally, the thermal peelability of the bump wafer was verified by heat treatment (heating in a hot air dryer at 120 ° C for 3 minutes). Furthermore, the thermal peelable double-sided adhesive sheet and the bump wafer are bonded together using the trade name. "DR3000II-WS" [Nitto Seiki Co., Ltd.], glass wafer bonding product name "MA-3000II-WS" [Nitto Seiki Co., Ltd.], and wafer grinding using product name "DFG-8460" [Manufactured by DISCO]. The results are shown in Table 1.

Furthermore, the bump height and the wafer thickness were directly measured by a 1/1000 mm gauge, and the bump pitch was measured by a digital microscope. The density of the porous base material (layer) (wherein Comparative Example 1 is a non-porous base material (layer) containing an acryl-urethane copolymer) was determined by the following at room temperature of 23 ° C. In a humidity of 50%, the sample size (vertical and horizontal) was measured with a steel ruler, the thickness was measured by a 1/1000 mm gauge, and the mass was measured by a weight of 1/1000 g, thereby obtaining the density by mass/volume. Regarding the tensile modulus, a tensile load measuring machine was used, and the initial elastic modulus was determined from the stress-bending curve.

[Table 1]

Industrial availability

The present invention relates to a heat-peelable double-sided adhesive sheet and a method of processing a processed body using the same. More specifically, it relates to the heat of the processed body which can be quickly reduced by the heat treatment and which is suitable for processing the surface unevenness. A peelable double-sided adhesive sheet, and a processing method of the processed body using the same.

1‧‧‧Substrate

2‧‧‧Hot peeling adhesive layer

3‧‧‧Adhesive layer

4‧‧‧Separator

Fig. 1 is a schematic cross-sectional view showing an example of a heat-peelable double-sided adhesive sheet of the present invention.

1‧‧‧Substrate

2‧‧‧Hot peeling adhesive layer

3‧‧‧Adhesive layer

4‧‧‧Separator

Claims (6)

A heat-peelable double-sided adhesive sheet which is provided with a heat-peelable adhesive layer A on one side of a substrate and a heat-peelable double-sided adhesive sheet on which an adhesive layer B is provided on the other side, and the above-mentioned base The material includes a porous substrate having a density of 0.9 g/cm ³ or less and a tensile modulus of 20 MPa or less. The heat-peelable double-sided adhesive sheet according to claim 1, wherein the substrate is composed of a laminate of a porous substrate and a non-porous substrate. The heat-peelable double-sided adhesive sheet according to claim 1 or 2, wherein the adhesive layer B comprises a pressure-sensitive adhesive, an ultraviolet-curable adhesive, a heat-peelable adhesive, a thermoformable adhesive or a thermosetting adhesive. . A method of processing a processed object, comprising: bonding any one of the heat-peelable adhesive layer A and the adhesive layer B of the heat-peelable double-sided adhesive sheet of any one of claims 1 to 3 The bonding step of bonding the support to the other body, the processing step of processing the object to be processed, and the peeling and recovering step of peeling and recovering the workpiece by heat treatment after processing the object. The processing method of the object to be processed according to claim 4, wherein the electronic component or the semiconductor wafer is processed. The processing method of the object to be processed according to claim 4 or 5, wherein the object to be processed having a surface having a maximum surface unevenness of 10 μm or more is bonded to the adhesive surface of the heat-peelable double-sided adhesive sheet and processed. By.